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영어

Sildenafil citrate, a potent and selective inhibitor of phosphodiesterase type-5, is used clinically to treat erectile dysfunction and pulmonary ar-terial hypertension. We investigated the effect of sildenafil citrate on brain central fatigue through serotonin (5-hydroxytryptamine, 5-HT) synthesis after exhaustive swimming exercise in rats. The rats in the sildenafil citrate-treated groups received sildenafil citrate orally once a day for 14 consecutive days at respective dosage. On the 14 days after starting experiment, each animal was submitted to swimming test with intensity equivalent to overload. The exhaustion was defined as a state in which coordinated movements did not return to the water surface for breathing within 10 sec. Immunohistochemistry for 5-HT, tryptophan hy-droxylase (TPH), and western blot for serotonergic type 1A (5-HT1A) re-ceptor and 5-HT transporter (5-HTT) were performed. Exhaustive swim-ming exercise increased 5-HT and TPH expressions in the dorsal raphe and sildenafil citrate suppressed 5-HT and TPH expressions in the ex-haustive swimming exercise rats. Exhaustive swimming exercise in-creased 5-HT1A receptor and 5-HTT expressions in the dorsal raphe and sildenafil citrate suppressed 5-HT1A receptor and 5-HTT expres-sions in the exhaustive swimming exercise rats. The significant sup-pressing effect appeared in the 20-mg/kg sildenafil citrate. Sildenafil ci-trate might be proposed as a potential ergogenic aid through anticentral fatigue.